Walker urged voters to call Baldwin's office to demand a fair hearing for Gorsuch while the National Republican Senatorial Committee launched a television ad taking on the first-term senator from Madison.

The GOP political push marks the opening salvo in the 2018 race that will pit Baldwin against a Republican challenger. It is also part of a month-long high court campaign as Republicans target Democratic senators who represent states that went for Trump in the fall election.

On Friday, Walker directed a string of tweets at Baldwin including one that said: "Hypocrisy: telling others to meet with #SCOTUS nominee in 2016, but announcing your vote on nominee in 2017 before a meeting"

Baldwin responded: "Is @ScottWalker trying to impress @POTUS with his tweets or does he want to run against me? I'm ready."

Hypocrisy: telling others to meet with #SCOTUS nominee in 2016, but announcing your vote on nominee in 2017 before a meeting.

Speaking to supporters in Waukesha on Saturday, Walker said: "There are plenty of great candidates for United States Senate, I am not one of them. If I run for anything it's going to be for re-election to be your governor. "

"I think that's pretty suspicious," Walker said. "I think it's fairly likely that the liberal, big-government special interests in Washington told her 'no, we're not going to fund your campaign, we're not going to support your efforts if you don't shut down this process and vote no.' "

"I think that's wrong," Walker said.

In 2016, Republican U.S. Sen. Ron Johnson joined a successful GOP blockade to prevent former President Barack Obama's high court nominee, Merrick Garland, from receiving a hearing.

Democrats appear poised to mount a Senate filibuster in an attempt to block the Gorsuch nomination. If successful, Republicans might trigger a so-called "nuclear option," scrapping the Senate's 60-vote threshold to confirm a Supreme Court nominee.

"President Trump and his nominee need to earn 60 votes in the Senate," Baldwin told the Journal Sentinel Thursday. "I will not be one of them."

The 30-second spot from the National Republican Senatorial Committee will air in the Green Bay market during Sunday's college basketball telecast of the University of Wisconsin's game against Indiana University.

Titled 'Irresponsible," the ad points to remarks Baldwin gave last year when she called on the U.S. Senate to consider Garland.

The ad says, "But now Baldwin and Democrats want to block a vote on Judge Neil Gorsuch..." An announcer says, "Tell Tammy Baldwin, put your country ahead of your party."

Democrats pushed back at the ad.

"Twenty-one months before the election, DC special interests are already polluting Wisconsin airwaves with attack ads," said Gillian Drummond, a spokeswoman for the Democratic Party of Wisconsin. "Tammy won't back down in her fight for Wisconsin, no matter what dirty attacks come from Washington."